WO2005016793A1

WO2005016793A1 - Waste bin

Info

Publication number: WO2005016793A1
Application number: PCT/GB2004/003499
Authority: WO
Inventors: Duncan Green; Helen O'driscoll
Original assignee: Duncan Green; Helen O'driscoll
Priority date: 2003-08-14
Filing date: 2004-08-16
Publication date: 2005-02-24

Abstract

A kitchen bin (1) has three main parts: tapered telescopic body (2), support base (3 )and removable rollback lid (4). The telescopic body (2) comprises four concentric ring sections (5). Each ring section (5) is slightly tapered to form a frusto-conical shape. The lowermost ring section (5a) has a closed base whereas the remaining ring sections (5b-d) are open at both ends. The upper rim of the lowermost section (5a) is received within the lower rim of section (5b) above it. Ring section (5b) likewise fits within section (5c) above it, as does (5c) within (5d). Uppermost rim section (5d) has push-down handles secured thereto, which are used for collapsing the bin. The lowermost ring section (5a) is removably connected to the support base (3) Removable rollback lid (4) is removably located on ring section (5d). There is sufficient clearance between the recess and the rim to allow a standard bin liner to be located between them in the conventional manner. In use the ring sections of the bin may be telescoped downwards to allow easy removal of the bin liner and its contents. The collapsed bin may then be cleaned in a conventional dishwasher, the spacing between the collapsed ring sections being determined to allow free flow of cleaning solution.

Description

Waste Bin The present invention relates to containers for receiving refuse, such as bins, and in particular, but not exclusively to the type of bins commonly found in domestic kitchens. There are many different types of waste containers available and their design varies widely depending on the nature of the waste matter. Waste paper baskets are of course well known; these are normally only suitable for matter such as paper that is not wet and will not rapidly decompose. In contrast, the type of bin normally found in a kitchen should be capable of retaining food waste that commonly has a high water content and is likely to decompose. It is therefore desirable that such bins will not leak liquid, should retain odours caused by the decomposition of food waste and they should be generally hygienic. Although waste may be contained directly by the bin, which may periodically be tipped into a dustbin, it is more common for bin liners to be used.

These are large, usually polythene, bags that fit within the bin. Typically the top part of the bin liner is folded back over the outside of the bin body to ensure that waste does not fall between the liner and the body. The bin is used in the normal way and when it is full the bag is removed for disposal with the waste inside it. The use of bin liners is intended to improve hygiene by preventing the waste from soiling the inside of the bin and to assist in emptying the bin. Unfortunately, they are at best only partially successful in achieving these ends. Most bin liners are not, in fact, waterproof. Even if the bag is originally well- sealed, sharp objects in the refuse may puncture it. This has the result that liquid from the waste will gradually seep through seams and into the bottom of the bin itself. This may not be noticed when the bin is emptied and the bin -liner replaced with the result that the inside of the bin becomes soiled and unhygienic. As well as being an unpleasant task, the size of many bins makes it practically difficult to clean them. Specifically the height of the bin is greater than a typical arm s length making reaching the inner bottom surface awkward. A further problem with the use of bin liners is that bins are often overfilled and this tends to wedge the bag within the bin. Furthermore, the liner may act like a piston in a cylinder: air cannot flow past it and so air pressure tends to hold the liner within the bin body. It is therefore often very difficult to remove the filled liner from the bin body. This can lead to the bin liner ripping around the neck causing waste to spill onto the floor which presents a health hazard. According to one aspect of the present invention there is provided a waste bin for use with a bin liner, the bin having a body arranged to receive a bin liner, the body being collapsible to facilitate removal of the liner when it is full of waste. Thus, the bin may be fitted with a bin liner and then used in the conventional way. Once the bin liner has been filled, it may be tied off, e.g. by knotting parts of its opening together or using a tie. However, instead of then trying to pull the bag from the bin, the user instead collapses the bin around the bag. The bag may then be removed. Subsequently, the bin is returned to its normal state and a new liner inserted. It will be seen that the invention also provides a novel way of using a waste bin and so, viewed from another aspect there is provided a method of using a waste bin comprising: providing a waste bin for use with a bin liner, the bin having a body arranged to receive a bin liner, the body being collapsible to facilitate removal of the liner when it is full of waste, locating a bin liner in the bin, placing waste material in the bin and subsequently removing the bin liner by collapsing the body of the bin. The bin may be any sort of waste container, but it is believed that the invention is of greatest utility in the context of small to medium sized refuse bins, particularly those used for waste food products and packaging, such as those found in domestic or restaurant kitchens. In its most preferred form the bin is a domestic kitchen bin. Preferably, the internal width of the bin at its widest part is between 20cm and 40cm, and more preferably is between 25cm and 35cm. The height of the bin is preferably not more than lm and, more preferably is between 30cm and 70cm and most preferably 50 to 60 cm. In one particularly preferred embodiment the height of the bin is about 56 cm. Preferably, the bin collapses in such a way that it may be retained in the collapsed state. This may be useful either for storage or, more significantly, to enable the bin to be placed in a cleaning apparatus such as a domestic dishwasher. The body will most commonly be an upright container, for example of square, rectangular, round or oval cross-section. However, any suitable shape may be used. Although the upright sides may be parallel, preferably, the sides are tapered such that the width of the bottom of the bin is less than that at the top. It will normally have a closed base, however, in some circumstances; for example, if dry waste is to be contained, or if the bin liners used will not leak then the base may be open. Likewise, openings may be foπned in the walls of the body. One possible construction for the body to facilitate collapsing is to form it from a member that may readily be shortened in length, e.g. it may use a concertina construction. A further possibility is to use a non-rigid material such as canvas in conjunction with a frame. The non-rigid material may be removed from the frame to collapse the bin, or the frame itself may be collapsible with the non -rigid material. It is, however, most preferred to form the body from a plurality of telescoping sections. These may be of any of the sectional shapes discussed above, but circular section (i.e. ring-like) is most preferred. It is most preferable for the height of each section to be sufficiently small so as to allow the bin once collapsed to fit easily into a domestic dishwasher. Preferably therefore, the height of each section is less than 18cm, more preferably between 12cm and 16 cm and, most preferably, 14cm. This will mean that the total height of the bin body when collapsed is between 16 and 18cm. The number of sections may be varied, but preferably there are three to five, and most preferably there are four, although three may be preferred in some designs. This number enables a standard sized bin to be collapsed to fit inside a conventional dishwasher. The individual sections may have parallel sides. Since they are arranged to telescope, each section will be larger or smaller than the adjacent one. The largest section may be at the bottom with the smallest at the top but it has been found that the bin may be emptied more easily if the wider sections are at the top. However, it is particularly preferred for the sections themselves to be tapered. This has the advantage that when the bin body is collapsed, there will be a space between the sections. Preferably the taper is such that the gap between sections is large enough to facilitate a flow of water between the sections if the collapsed body is placed in a dishwasher. The flow should be sufficient to allow the interior of the bin to be cleaned. Preferably therefore the space between the sections is between 5mm and 25mm. The space between each section does not have to be the same, for example there may be a space of S-12mm (e.g. 10mm) between one pair of sections and 18- 22mm (e.g. 20mm) between another. In a bin with three sections these spacings can be used with the wider gap between the middle and bottom sections to facilitate removal of the base. Spacings such as these enable the whole of the interior of the bin to be cleaned, whilst preventing the bin from becoming overly tapered in shape.

In another embodiment, the space between the sections is about 1cm. These measurements refer to the distances between the walls of the sections. There may be small areas where the spacing is different, for example, to accommodate the structural components of the bin. The lowermost section may have a closed bottom part; the remaining sections would normally be open at both ends. A frame, external clips, etc. may be used in order to hold the sections in the non-collapsed configuration. HoAvever, it is preferred for the sections to comprise co-operating members such as integral clips or catches to lock them together. Most preferably, the sections are provided with integral projections and cooperating resilient members. These may snap into the locked position as the body is extended. In order to enable the whole bin to be collapsed by pressing down on the upper section, the sections are preferably arranged such that when pressure is applied, the sections collapse one at a time from the bottom so that the upper section is the last to slide over the one beneath it. This may be achieved by providing resilient members in the upper sections that require a greater force to deform them (and members requiring correspondingly less force in the lower sections). Ease of collapsing may further be improved by the provision of handles on the upper section. These may be pushed downwards to collapse the bin. It is particularly preferred that the body also be constructed so that it may readily be taken apart for cleaning by hand. Although the bin may comprise just the body described above, its stability may be improved by the provision of a base. Preferably the base has a width that is significantly greater than that of the lower section of the body. It may also have a surface on which the user may place his foot to hold the bin as the bin liner is removed. The base is preferably detachable to facilitate dismantling of the bin. Most preferably, removal of the base allows the sections of the body to be separated. The base may be attached to the lower section by means of a bayonet arrangement or other suitable releasable connector. As noted above, the spacing between the loλver section and the adjacent one may be chosen to facilitate removal of the base, e.g. by providing sufficient space to allow that section to be gripped by hand and rotated. In some environments the bin of the invention may not be provided with a lid, but in order to retain odours and to provide a more attractive appearance, it is preferred to provide one. The lid may be a. removable one as found in dustbins, or one of the other knoλvn kitchen bin lid systems may be employed. One well-knoλvn bin lid system is that found on a "swing bin". The bin is normally made of a plastics material. It usually has an upstanding body of generally square section for retaining waste and the lid that is placed on top of the body. The lid is shaped like the pitched roof of a house. It is formed in two pieces with the sloping parts, which are integral with each other, forming one opening part and the remainder forming a frame. The opening part is pivoted to the frame with the ridge- line as the pivot axis. The opening part therefore normally falls into the closed position. When it is desired to put waste into the bin, the opening part is swung to one side to provide an opening. However, to use such a lid hygienically, one hand has to be used to hold it open while the other deposits the waste. Many users find this inconvenient with the result that the lid is commonly swung open by pushing the waste material against the opening part of the lid. This results in the exterior of the lid becoming soiled. This results in a likely build up of bacteria and is a clear hygiene risk. A further problem is that there must be sufficient room within the bin to allow the lid to swing open. If it is over -filled, the opening part will be obstructed.

The "pedal bin", which is another well-known design, addresses these problems to some extent. Here the bin body is more commonly cylindrical with a basically disc- shaped lid that is pivoted near its circumference to the body. A foot -pedal is provided near the bottom of the bin and this is connected to a mechanism that opens the lid when the pedal is depressed. However, pedal bins also have significant disadvantages. The pedal and the bin need to provide space for the lid to open away from the bin increasing the footprint of the bin beyond that required simply to contain the waste. Also, such bins must be placed at floor level to allow access to the pedal. Finally, it will be appreciated that in the context of the present invention, providing the lid opening mechanism for a collapsible bin complicated the design. It is therefore preferred that the lid itself is arranged to collapse into a smaller size as it is opened. Preferably it is formed from a number of sections that are caused to overlap as the lid is opened. In one preferred form, the height of the lid when collapsed is less than 14cm. A particularly preferred form is to use a plurality of nested part-spheres that are pivoted together at their poles so that when closed they form a hemisphere. When nested (open) a large opening may be provided. This provides an attractive form whilst also providing some headspace in the bin, If desired the sections may be biased into the closed condition but this does not allow single-handed operation. Preferably, therefore the sections remain in the open position until closed which allows for hygienic single-handed operation. Optionally, the lid may be fitted with a slow returning spring mechanism which automatically closes the lid. Additionally a clasp mechanism may be fitted to the lid in order to secure the lid in the closed position, The lid may also be provided with a handle to assist in opening and closing. There should preferably be sufficient clearance between adjacent sections of the lid so as to facilitate the free flow of water between its surfaces when washing in the dishwasher. This form of lid is itself regarded as an invention and so from another aspect there is provided a lid for a bin which is formed from a number of sections that are caused to overlap as the lid is opened. The sections are preferably configured as described above. Although the bin has been described in the context of using it with a bin liner, it may of course be used without one. In this mode of use the ability to clean it easily is particularly valuable. It is recognised that the telescoping section described above may even be specially constructed for use without a bin liner. For example, seals may be provided to prevent leakage between the sections. Furthermore, it is recognised that the structures described above may be used for other purposes than containing waste, either in a domestic or non-domestic environment. Thus, viewed from a still further aspect there is provided a container comprising a body formed of a plurality of telescoping sections. Such a container preferably has the other preferred features discussed above, The provision of a bin which may be collapsed and then cleaned in a domestic dislrwasher' is considered to be novel and inventive in its own right and so, from a further aspect, the present invention provides a bin comprising a body foπned of a plurality of telescoping sections, the height of each section being sufficiently small so as to allow the bin to fit into a domestic dishwasher when collapsed. Such a bin may preferably have any of the other preferred features discussed above, It is preferably manufactured from dishwasher-grade plastics to allow regular cleaning and to avoid damage to the inside of the dishwasher. From a still further aspect, the present invention provides a bin comprising a body formed of a plurality of telescoping sections, wherein the sections are tapered such that a space is provided between the sections when the body is collapsed, the space being large enough to facilitate a flow of water between the sections when the collapsed bin body is placed in a domestic dishwasher such that the interior of the bin may thereby be cleaned. Thus, the bin may be placed in a conventional domestic dishwasher by collapsing the telescoping sections. Cleaning of the bin in a dishwasher is facilitated by the spaces that are then provided between the sections, There is preferably a space of at least 5mm between the walls of the adjacent sections of the collapsed bin, and more preferably the spacings described above are used. Such a bin may preferably have any of the other preferred features discussed above. From a still further aspect, the present invention provides a method of cleaning a bin comprising a body formed of a plurality of collapsible telescoping sections, the sections being tapered such that a space is provided between the sections when the body is collapsed, the method comprising collapsing the bin body and placing the bin in a domestic dishwasher such that the interior of the bin may thereby be cleaned, the space between the sections being large enough to facilitate a flow of water between the sections. The bin of the method may preferably have any of the preferred features discussed above. An embodiment of the invention will now be described, by way of example only, and with reference to the accompanying drawings: Figure 1 is a perspective view of a bin according to the invention; Figure 2 is an exploded view of the bin of figure Figure 3 is a view of the bin with its lid removed; Figure 4 A is a side view of a central part of the bin showing the connection between two ring sections; Figure 4B is a sectional view corresponding to part of Figure 4 A; Figures 5A-D are views corresponding generally to Figure 4B showing the movement of one section relative to another as the bin is collapsed; Figures 6A1-D2 are side views and corresponding schematic views of the lid of the bin as it is moved from its closed to its open position; Figure 7A is an underneath perspective view of the lowermost ring section; Figure 7B is an enlarged view of part of Figure 7 A showing a locking nut; Figure 8 A is a perspective view of the base of the bin; Figure SB is an enlarged view of part of Figure 8 A showing a slot for receiving the locking nut; Figures 9A and B are perspective views showing the interconnection of the lowermost ring section with the base; Figure 9C is an enlarged view of a portion of Figure 9B with the locking nut in the locked position; Figures 10A-D are a series of perspective views of the bin with its lid removed showing the steps of collapsing the bin to facilitate removal of a full bin liner. Figures 11A-D are a series of perspective views of the bin in its collapsed state showing its disassembly to facilitate cleaning by hand; Figure 12A is a side view of a central part of a second embodiment of bin showing the connection between two ring sections; Figure 12B is a sectional view corresponding to part of figure 12A; Figures 13A-C are views corresponding generally to Figure 12B showing the movement of one section relative to another as the bin is collapsed; Figure 14 is a cross sectional perspective view of the upper ring section of the bin of figure 12 A; Figure 15 is a cross sectional perspective view of the middle ring section of the bin of figure 12 A; Figures 16A-C are perspective views of the bin of figure 12A with its lid removed showing the steps of collapsing the bin to facilitate removal of a full bin liner, As may be seen from figures 1 and 2, a bin 1 according to an embodiment of the invention has three main parts: tapered telescopic body 2, support base 3 and removable rollback lid 4. Each of these main parts is moulded from tough dishwasher-resistant plastics material. The bin is for use as a domestic waste bin, and particularly as a kitchen bin. Thus, the total height of the bin when assembled is

56cm and the width of the widest part thereof is 30cm. The telescopic body 2 comprises four concentric ring sections 5. Each ring section 5 is slightly tapered to form a frusto-conical shape. The lowermost ring section 5a has a closed base whereas the remaining ring sections 5b-d are open at both ends. The upper rim of the lowermost section 5a is received within the lower rim of section 5b above it. Ring section 5b likewise fits within section 5c above it, as does 5c within 5d. As will be described below, the sections may be locked together in the configuration illustrated in figure 1 or figure 3 (where the lid is removed) to provide a bin body. Uppermost rim section 5d has push-down handles secured thereto, which are used for collapsing the bin. The lowermost ring section 5a is removably connected to the support base 3 as will be described below, This provides additional stability to the bin. Removable rollback lid 4 is removably located on ring section 5d. Its lower rim 10 is configured to engage on the upper rim of that section which is received into a recess in the rim. There is sufficient clearance between the recess and the rim to allow a standard bin liner to be located between them in the conventional manner. The lid is formed from four nested sections lla-d of a hemisphere. Section 11a fits over section lib and so on, The sections are all connected together and to rim 10 by pivots 9. The pivots allow the sections to nest in order to provide an opening into the bin. Again, this is described in more detail below, Handle 7 is mounted on section 11a to facilitate opening. This handle may rotate freely around its axis so that as the user pushes the lid into the open position he or she does not have to shift his or her grip on the handle. Turning now to figures 4a and 4b, the interconnection between adjacent ring sections will now be described. Upper rim 12 of ring section 5b is shown located within the lower rim 3 of ring section 5c in the fully extended configuration - i.e. as when the bin is in use. As may be seen from that figure, lower rim 13 is castellated to form a series of depending flexible arms 14. These are resiliently biased against the wall of rim 12 and are located above protruding ridge 15 formed in that rim. The interconnection between the rims 12 and 13 can be understood more clearly with reference to figure 4B. The inside face of rim 13 is provided with flange

16 and the outside face of rim 12 if provided with a corresponding flange 17, As may be seen from the figure, in the extended configuration of the bin that is illustrated, the two flanges abut, thereby limiting the travel of upper ring 5c relative to lower-ring 5b. Thus, this provides a stop which prevents the rings from separating and provides a seal between the two rings. In addition, it may be seen that the lowermost end of flexible arm 14 is located above protruding ridge 15. Since the flexible arm is resiliently biased towards rim 12, the arm is held above ridge 15, which in turn prevents ring 5c from falling down over ring 5b. However, as will now be described with reference to figures 5A-D, the arrangement just described allows the upper ring selectively to be moved down over the lower one (and likewise for the other rings) in order to collapse the bin. As shown in figure 5A, the user applies moderate downward pressure by pressing down on the upper ring Sc, As the upper ring moves downwards (figure 5B), the flexible arm 14 pushes against the protrusion 15 on the lower ring 5b. The arm 14 flexes outwards in order to pass over the protrusion. The protrusion 15 has a shallow incline and only a moderate amount of pressure is required for the arm 14 to pass over it. Once the arm 14 has passed over the protrusion (figure 5C), it returns to its original angle and continues to press against the outer surface of the lower ring. The arm maintains contact with the surface of the lower ring 5b as the upper ring Sc slides downwards. This keeps the downward motion controlled and smooth. At the base of the lower ring 5b there is a second protrusion 18 which stops the descent of the upper ring. This is larger than protrusion 15. As the user continues to apply moderate pressure to the upper ring 5c, the downward force is transferred to the lower ring 5b which begins its descent over the ring 5a beneath it. (Since protrusion 18 is larger than protrusion 15, in order for the arm 14 to slide over the lower protrusion, firm downward pressure must be applied. This is done when the user wishes to disassemble the bin.) Figures 6A1-6D1 and the corresponding views of figures 6A2-6D2 illustrate the operation of the lid 4. As discussed above, this comprises four sections lla-lld which are all sections of spheres. They pivot at point 9 (and likewise on the opposite side) and are nested so that 11a fits over lib and so on. It is important to note that the sections are provided with overlapping flanges 20 and 21 , Flange 21 of section 11a extends both radially inwardly and outwardly. Flange 20 extends only outwardly. The flanges extend across the circumferences of the sections almost from pivot 9 to the opposite pivot. In the configuration shown in figures 6A, the inwardly projecting part of flange 21 of section 11a rests on radially outwardly projecting flange 20 of section lib. This provides a partial seal between the two adjacent sections. In addition, this arrangement interconnects the sections 50 that when the lid is closed, as one section is moved, it engages the adjacent one inside it. The outwardly projecting part of flange 21 causes the sections to engage as the lid is opened. For example, outer flange part 22 (figure 6A2) will be engaged by flange 21 as the lid is opened. This is illustrated in the remaining draλvings of figure 6. As may be seen in figures 6B, section 11a which is connected directly to handle 7 is moved first as the lid is opened. When it reaches the position shown in figures 6b it engages section lib. As section 11a is moved further, it moves section lib with it until, as shown in figure όC section lie is also engaged. Sections 11a, lib and lie then all move back together until they are all fully over section lid in the position shoλvn in figure 6D. To close the lid, section 11a again moves first. It moves by itself until flange 21 engages flange 20 of section lib. The sections are then moved together until section lie is also engaged and the lid is returned to the configuration of figure 6A. Support base 3 is removably attached to the bottom of lowermost ring section 5a. As shown in figure 7, the ring section 5a has a protruding locking nut 25 which can be turned one-quarter turn, As may be seen in figure 8, the base 3 has a slot 26 at the centre into which the locking nut slides. Figures 9A and 9B show the engagement of these'components as the base 3 is presented to the ring section 5a, the nut 25 is inserted through slot 26 and (figure 9C) the locking nut is rotated one quarter turn to lock the base and bottom ring together. As noted above, in normal use, a bin liner is placed between lid 4 and the bin body 2 so that the liner lines the inside of the bin body in the conventional manner. This is fitted by removing lid 4, locating the liner and then replacing the lid. In order to put refuse into the bin, the lid is opened in the manner described with reference to figures 6 and the lid is closed again. It will be noted that because of the construction of the lid, even if the bin is nearly full, the lid may still easily be opened. Further, the lid provides a wide aperture and remains securely in the open position until closed. Thus, the bin may be operated with one hand without the risk of contaminating the outside of the lid. When the bin is full, the lid is removed. The bin liner may then be removed. It is tied off, but instead of trying to pull it out, which can be difficult with the prior art bins, the procedure illustrated in figures 10A-D is used. As shown in figure 6A, the operator pushes down firmly on handles 6. This causes ring section 5d to slide down over section 5c as described above with reference to figures 4. Section 5d will then engage with section 5c (figure 10B) and the two sections then move downwards together, exposing the bin liner. In a similar manner, section 5b is engaged (figure IOC) and so finally sections 5b-d move down until they reach the base (figure 10D). The bin liner can then easily be removed. The bin may now be cleaned. If the operator has access to a dishwasher, the bin body 2 (attached to base 3) and the lid 1 may be placed separately inside it. This is done with the lid in the closed position so that the entire inside may be cleaned. With regard to the bin body 2, because the ring sections are frus to-conical, once the bin is fully collapsed a clear space is provided between each ring. This means that if the assembly is placed base-upwards in the dishwasher, the washer-jets will spray inside each of the sections, thereby allowing them to be cleaned efficiently. In the embodiment shown, each ring section has a height of 14cm. Thus, the total height of the bin body 2 when collapsed is between 16 and 18cm, this being the maximum height that can be efficiently loaded into a dishwasher. Further, the space provided between each ring when the bin is in the collapsed state is 1cm. This provides for sufficient cleaning between the rings when the bin is washed in a dishwasher. However, if the user does not have access to a dishwasher, the bin may easily be disassembled for cleaning. First, the base is removed in the reverse procedure to that shown in figures 9A-C. Then the lower (and innermost) ring section 5a can be removed. As shown in figure 11A, this is done by applying sufficient force to cause flexible arms 14 of the adjacent ring to pass over protrusion 18. The same procedure is then repeated for the other rings - see figures UB-D. The separate parts of the bin can then be washed by hand before reassembly by reversing the procedure above. A second embodiment of bin will now be described with reference to the remaining figures. The complete bin body is shown in Figure 16 A. It may be provided with a lid as described above or a conventional lid. It will be noted that this bin has only three ring sections but is otherwise similar to the first embodiment and so only the features which are different will be described in detail. Turning now to figures 12A and 12B, the interconnection between adjacent ring sections will now be described. Upper rim 12 of ring section 5b is shown located within the lower rim 13 of ring section 5c in the fully extended configuration

- i.e. as when the bin is in use. The upper rim 12 is castellated to form a series of depending flexible arms 104a. These are resiliently biased against the inner wall of rim 13 and, in the fully extended configuration, are located between ramp 104b and ridge 104e formed in that rim. The arrangement of these features may be better understood by referring to figures 14 and 15. The interconnection between the rims 12 and 13 can be understood more clearly with reference to figure 12B. The inside face of rim 13 is provided with stop

104c and the outside face of rim 12 is provided with a corresponding stop 104d. As may be seen from the figure, in the extended configuration of the bin that is illustrated, the two stops abut, thereby limiting the travel of upper ring 5c relative to lower ring 5b, Thus, this provides a stop which prevents the rings from separating and provides a seal between the two rings. In addition, it may be seen that the uppermost end of flexible arm 104a is located between ramp 104b and ridge 104e. Since the flexible arm is resiliently biased towards rim 13, the arm is held below ramp 104b, which in turn prevents ring 5c from falling down over ring 5b. As shown in figure 13 A, when it is desired to collapse the bin, the user applies firm downward pressure by pressing down on the upper ring 5c. As the upper ring moves downwards (figure 13B), the flexible arm 104a pushes against the lower face of ramp 104b located on the upper ring 5 c. The arm flexes inwards in order to pass over the ramp 104b. The lower face of the ramp has a sharp incline so firm pressure is required. Once the arm has passed over ramp 104b, it returns to its original angle allowing upper ring 5c. to continue downwards. The degree of incline of the lower face of ramp 104b determines the amount of pressure that must be applied in order to collapse each ring section of the bin. Figures 16A-C illustrate the order in which the ring sections of the bin should collapse. The order in which the ring sections collapse is controlled by varying the angle of incline of the lower face of ramp 104b, On the lower ring sections of the bin it is at a more shallow incline than that of the corresponding ramp on the upper sections. This ensures that when the user applies firm downward pressure to the upper rim of the topmost ring section, the lower ring sections collapse first. The lower sections must collapse before the upper sections to ensure correct operation of the bin. Once collapsed there is an even radial gap of about 10mm between the upper ring and the middle rings and a gap of about 20mm between the middle and lower rings. Once the bin has been collapsed it may be placed in a dishwasher for cleaning as in the first embodiment, Alternatively, it may be dismantled. In this case, after collapsing, the base is removed. This is done by rotating the lower ring relative to the base. The larger gap between these rings facilitated gripping of the lower ring. These components are connected by a bayonet arrangement (not shown) so that rotation of 20-30 degrees releases the base. Once the base has been removed, the rings can then be separated in sequence, The separate parts may then be washed by hand,

Claims

1. A waste bin for use with a bin liner, the bin having a body arranged to receive a bin liner, the body being collapsible to facilitate removal of the liner when it is full of waste,

2. A waste bin as claimed in claim 1, wherein it may be retained in the collapsed state for cleaning.

3. A waste bin as claimed in claim 1 or 2, wherein the sides are tapered such that the bottom is smaller in section than the top.

4. A waste bin as claimed in claim 1 , 2 or 3, wherein the body comprises a plurality of telescoping sections.

5. A waste bin as claimed in claim 4, wherein the sections are each tapered.

6. A waste bin as claimed in claim 5, wherein the taper is such that the gap between sections is large enough to facilitate a flow of water between the sections if the collapsed body is placed in a dishwasher.

7. A waste bin as claimed in claim 6, wherein the space between the sections is between 5mm and 25mm.

8. A waste bin as claimed in any of claims 4 to 7, further comprising handles on the upper section which may be pushed downwards to collapse the bin.

9. A waste bin as claimed in any preceding claim wherein the body may readily be taken apart for cleaning by hand.

10. A waste bin as claimed in any preceding claim, further comprising a base.

1 1. A λvaste bin as claimed in claim 10, wherein the base has a surface on which the user may place his foot to hold the bin as the bin liner is removed.

12. A waste bin as claimed in claim 10 or 1 1, wherein the base is detachable to facilitate dismantling of the bin.

13. A waste bin as claimed in any preceding claim, further comprising a lid.

14. A waste bin as claimed in claim 13, wherein the lid is arranged to collapse into a smaller size as it is opened. 15 A waste bin as claimed in claim 13 or 14, wherein the lid comprises a number of sections that are caused to overlap as the lid is opened. 16. A waste bin as claimed in any of claims 13 to 15, wherein the lid comprises a plurality of nested part-spheres that are pivoted together at their poles so that when closed they form a hemisphere 17 A waste bin comprising a body formed of a plurality of telescoping sections, the height of each section being sufficiently small so as to allow the bin to fit into a domestic dishwasher when collapsed. 18. A waste bin comprising a body formed of a plurality of telescoping sections, wherein the sections are tapered such that a space is provided between the sections when the body is collapsed, the space being large enough to facilitate a flow of water between the sections when the collapsed bin body is placed in a domestic dishwasher such that the interior of the bin may thereby be cleaned. 19 A method of using a waste bin comprising: (a) providing a waste bin for use with a bin liner, the bin having a body arranged to receive a bin liner, the body being collapsible to facilitate removal of the liner when it is full of waste, (b) locating a bin liner in the bin, placing waste material in the bin, and (c) subsequently removing the bin liner by collapsing the body of the bin. 20. A method of cleaning a bin comprising a body formed of a plurality of collapsible telescoping sections, the sections being tapered such that a space is provided between the sections when the body is collapsed, the method comprising collapsing the bin body and placing the bin in a domestic dishwasher such that the interior of the bin may thereby be cleaned, the space between the sections being large enough to facilitate a flow of water between the sections